Добавлены тесты скидок и функция getTotalDiscount

server/babel.config.js

@@ -0,0 +1 @@
+module.exports = {presets: ['@babel/preset-env']}

server/package.json

@@ -71,18 +71,20 @@
     "eslint-plugin-jsx-a11y": "^6.4.1",
     "eslint-plugin-prettier": "^3.4.0",
     "fs": "^0.0.1-security",
-    "jest": "^29.0.0",
+    "jest": "^29.7.0",
     "path": "^0.12.7",
     "prettier": "^2.3.2",
-    "ts-jest": "^29.1.1",
+    "ts-jest": "^29.2.4",
     "ts-loader": "^9.2.5",
     "ts-node": "^10.9.1",
     "typescript": "^5.2.2"
   },
   "dependencies": {
     "@apollo/server": "^4.9.3",
+    "@babel/preset-env": "^7.25.3",
     "@graphql-tools/schema": "^10.0.0",
     "apollo-server-express": "^3.1.2",
+    "babel-jest": "^29.7.0",
     "bcrypt": "^5.0.1",
     "cors": "^2.8.5",
     "crypto": "^1.0.1",

server/src/utils/discount/const.ts

@@ -0,0 +1,13 @@
+export enum TypeOfUser {
+    STANDARD = 'STANDARD',
+    PREMIUM = 'PREMIUM',
+    GOLD = 'GOLD',
+    FREE = 'FREE',
+}
+
+export enum TypeOfProduct {
+    CAR = 'CAR',
+    TOY = 'TOY',
+    FOOD = 'FOOD',
+}
+

server/src/utils/discount/discountHelper.test.ts

@@ -0,0 +1,43 @@
+import { describe, it, expect, beforeAll} from "@jest/globals"
+import { TypeOfProduct, TypeOfUser } from "./const"
+import { DiscountUnionType, getTotalDiscount } from "./discountHelper"
+
+describe('Check user and product discounts', () => {
+    let discountUserGold : DiscountUnionType;
+    let discountUserPremium: DiscountUnionType;
+
+    let discountProductFood: DiscountUnionType;
+    let discountProductToy: DiscountUnionType;
+
+    beforeAll(() => {
+        discountUserGold = {
+            type: 'user',
+            discountType: TypeOfUser.GOLD,
+        }
+        discountUserPremium = {
+            type: 'user',
+            discountType: TypeOfUser.PREMIUM,
+        }
+
+        discountProductFood = {
+            type: 'product',
+            discountType: TypeOfProduct.FOOD,
+        }
+        discountProductToy = {
+            type: 'product',
+            discountType: TypeOfProduct.TOY,
+        }
+
+    })
+
+    it('Check user Gold and product Food', () => {
+        let allDiscounts : DiscountUnionType[] = [discountUserGold, discountProductFood];
+        expect(getTotalDiscount(allDiscounts)).toBe(22);
+    });
+
+    it('Check user Premium and product Toy', () => {
+        let allDiscounts : DiscountUnionType[] = [discountUserPremium, discountProductToy];
+        expect(getTotalDiscount(allDiscounts)).toBe(17);
+    });
+
+})

server/src/utils/discount/discountHelper.ts

@@ -0,0 +1,74 @@
+import { TypeOfProduct, TypeOfUser } from "./const";
+// Вспомогательные функции для вычисления скидки пользователя
+// с учетом статуса пользователя и категории товара
+
+// Получение размера скидки по типу пользователя
+export const getDiscountByTypeOfUser = (type: TypeOfUser): number => {
+    switch (type) {
+        case TypeOfUser.STANDARD:
+            return 0;
+        case TypeOfUser.PREMIUM:
+            return 8;
+        case TypeOfUser.GOLD:
+            return 16;
+        case TypeOfUser.FREE:
+            return 100;
+        default:
+            return 0;
+    }
+}
+
+const getDiscountByTypeOfProductTypeGuard = (type: never): never => {
+    throw new Error('Function getDiscountByTypeOfProduct called with new type that it knows nothing about')
+}
+
+// Получение размера скидки по типу продукта
+export const getDiscountByTypeOfProduct = (type: TypeOfProduct): number => {
+    switch (type) {
+        case TypeOfProduct.CAR:
+            return 3;
+        case TypeOfProduct.FOOD:
+            return 6;
+        case TypeOfProduct.TOY:
+            return 9;
+        default:
+            return getDiscountByTypeOfProductTypeGuard(type);
+    }
+}
+
+export interface DiscountUnionType {
+    type: 'user' | 'product',
+    discountType: TypeOfUser | TypeOfProduct,
+}
+
+const getTotalDiscountTypeGuard = (type: never): never => {
+    throw new Error('Function getTotalDiscount called with new type that it knows nothing about');
+}
+
+// Получение общей скидки
+export const getTotalDiscount = (allDiscounts: DiscountUnionType[]) => {
+    let totalDiscount = 0;
+
+    allDiscounts.forEach(d => {
+        switch (d.type) {
+            case 'user': {
+                totalDiscount += getDiscountByTypeOfUser(d.discountType as TypeOfUser);
+                break;
+            }
+
+            case 'product': {
+                totalDiscount += getDiscountByTypeOfProduct(d.discountType as TypeOfProduct);
+                break;
+            }
+            default:
+                getTotalDiscountTypeGuard(d.type);
+        }
+    });
+
+    if(totalDiscount > 100){
+        totalDiscount = 100;
+    }
+
+    return totalDiscount;
+}
+